Prostate specific antigen (PSA) level test in blood has been widely implemented for the early detection and prediction of prostate cancer (PCa). However, lack of specificity led to overdiagnosis, following by unnecessary biopsies and overtreatment. Therefore, novel serological biomarkers are urgently needed to complement PSA by enhancing its sensitivity and specificity in the diagnosis of PCa. Autoantibodies against intracellular tumor associated antigens (TAAs) are commonly found in various types of human cancers. Their utility in providing insights into tumor biology and as potential cancer biomarkers is well documented. Previous studies have demonstrated that sera from patients with PCa contain autoantibodies that react with TAAs. In this study, we identified and characterized nucleophosmin 1 (NPM1) with 33 kDa molecular weight as an autoantigen by using serological proteomics analysis (SERPA) approach. In the further validation study, it was observed that the level of anti-NPM1 in sera from patients with PCa was significantly higher than that from benign prostatic hyperplasia (BPH) and healthy individuals and receiver operating characteristic (ROC) curve analysis showed high diagnostic value for PCa (area under the curve (AUC):0.805). Interestingly, when considering anti-NPM1 combined with PSA level in sera from PCa patients at the early stage as well as BPH, 100% PCa patients could be identified correctly, while 69.2% patients with BPH who has elevated PSA level were found anti-NPM1 negative. The data suggested that anti-NPM1 can elicit humoral immune response in PCa and might be a potential biomarker for the immunodiagnosis of PCa, and it would be a supplementary of PSA examination to distinguish PCa from BPH.

Key words: prostate cancer; nucleophosmin 1 (NPM1); tumor-associated antigens (TAAs); autoantibodies; serological proteomics analysis (SERPA)

Citation Format: jitian li, Liping Dai, Ningjing Lei, Mengtao Xing, Carlos A. Casiano, Jianying Zhang. Using serological proteomics analysis to identify anti-nucleophosmin 1 autoantibody in sera from prostate cancer patients as potential diagnositic and prognostic biomarker. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 4974.